Internal-combustion motor



A. B. NORTON.

INTERNAL COMBUSTION MOTOR.

APPLICATION FILED OCT. 20. I916. RENEWED OCT 24. 1919.

1,31 1,242, Patented Jul 29, 1919.

gnve'n ro'c 7 My K W ALLEN B. NORTON, OF DETROIT, MICHIGAN.

INTERNAL-COMBUSTION MOTOR.

Specification of Letters Patent.

Patented July 29, 1919.

' Application filed October 20, 1916, Serial No. 126,718. Renewed October 24, 1918. Serial No. 259,597.

To all whom it may concern: 7

Be it knownthat I, ALLEN B, NoR'roN, a citizen of the United States, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Internal-Combustion Motors, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to animproved form ofcylinder and piston construction for internal combustion motors.

With the main object of lessening the Weight of internal combustion engines it has heretofore been proposed to make the cylinder casting and the piston of metallic alloys of low specific gravity, such as the alloys of aluminum. Insu'ch cases the cylinder casting has been fitted with a lining sleeve of iron or steel to take the Wear of the piston and its packing rings.- While engines of this character mark a notable advance over earlier heavy forms of construction, there have been some disadvantages incident to the cylinder liners used. Thus it has been found that While some advantages accrue from the use of a relatively thin and uniform lining sleeve of ferrous metal, as

compared with a unitary cylinder casting of iron, nevertheless, because of the marked difference in the coefficient of thermal expansion of the metallic alloy of the piston and the ferrous metal of the liner, it has been necessary to provide a comparatively large clearance between the piston and the liner to avoid seizing when the motor heats up in operation. This large clearance causes piston slap and oil pumping when the motor is starting and for that reason is highly 0bjectionable. Furthermore, by reason of the fact that the thermal conductivities of the alloy metals of the piston and of the cylinder casting are materially higher than that of the iron or steel liner, the distribution of the heat in the liner is not as uniform as it would otherwise be and unequal expansion and distortion of the liner results.

The principal object of the present invention is the provision of a light weight motor in which the above mentioned disadvantages are avoided, and this object, as well as others which will later appear, are attained by the use of a composite cylinder comprising an outer casting of light weight metallic alloy and a cylinder sleeve or liner therein and made of metallic alloy having suitable wearresisting qualities, a high thermal conductivity and a coefficient of thermal expansion approximating that of the light weight alloy of the casting, and, in connection with such composite cylinder, a piston of light weight metallic alloy having a coefficient of thermal expansion approximating those of the cylinder casting and liner. The outer casting of the cylinder may be of any of the suitable known forms with which sleeves or liners are employed.

In order that the practice of my invention may be clearly understood, I will now descrrbe a preferred form of construction which is shown in the accompanying drawing.

In the drawing- Figure 1 is a transverse vertical section through one of the cylinders of an engine embodying my improvements.

Fig. 2 is a simlilar fragmentary section showlng a modified form of construction.

Referring in detail to the construction illustrated, 1 designates the cylinder casting in its entirety, said casting comprising the cylinder wall 1, the water jacket l suitable intake and exhaust valve passages, and .the upper crank case section 1". The cylinder casting is formed of alloy metal of low specific gravity, preferably aluminum alloy of suitable composition for the purose.

The cylinder casting has its main cylindrical chamber bored out to receive a lining sleeve 2 made of alloy metal having high Wear-resisting qualities, a high coeflicient of thermal conductivity and a coeflicient of thermal expansion approximating that of the aluminum alloy of the cylinder casting. Alloys of various composition may be employed for the liner with varying degrees of success. Certain of the aluminum alloys when probably cast or wrought have very considerable wear-resisting qualities, excellent antli-friction qualities, high thermal conductivities and coefiicients of expansion very closely approximating those ofthe aluminum alloys suitable for the outer cylinder casting. However, I prefer to use for the liner alloys having copper as their principal and characterizing constituent. Alloys of this character, such as the bronzes, I have found specially advantageous, as they possess very excellent wear-resistance qualities, are easily machined, and, at the same time, have relatively high coeflicients of thermal conductivity and icoefficients of thermal expansion approximating those of the aluminum alloy of the cylinder casting. A further advantage incident to the use of a liner such as described is the fact that the liner can be secured in the cylinder either mechanically or by pouring. the molten metal of the cylinder casting against the solid metal of the liner in" process of casting. In Fig. 1 I show the former construction in which the cylindrical chamber of the casting is bored out to receive the sleeve which is carefully machined to fit the bore of the"casting,c,lose metalliecontact between the parts being thus secured.

In Fig. 2 I indicate the second formof construction in which the sleeve is cast in. This method of construction can be very advantageously followed with a lining sleeve of material such as those above described inasmuch as the two metals are fused or welded together, when the molten metal to form the outer casting is poured against the solid metal sleeve and, as their coeflicients of thermal expansion are approximately the same, a very perfect and permanent union of the parts is secured.

The liner is generally made of uniform thickness throughout except that it is preferably provided at its upper end,'especia1ly when it is mechanically secured in place,

with an out-turned flange 2*, which fits in a corresponding countersink in the upper end of the cylinder casting.

The upper end of the cylinder is closed 'by a head casting designated as an entirety by 4, this casting having a water jacket 4 communicating in the usual and well known manner with the water jacket 1 of the cylinder casting. The combustion space 5 formed in the head casting has an extension 5 which communicates with the inlet and exhaust passages through valve controlled openings in the usual manner; in the drawing the exhaust valve is shown at 6 and it will be understood that the inlet valve is in that part of the structure which does not appear.

In the form of construction shown in Fig. 1 the sleeve 2 may be secured in the cylinder in any desired manner but is preferably clamped in place by the head casting 4 which engages the out-turned flange 2 and is securely attached to the cylinder casting.

7 designates a piston arranged to reciprocate in the cylinder in the usual manner, being connected by a connecting rod 8 with the crank 9 of the engine shaft 10.

The piston is made of light weight metallic alloy having a coefficient of expansion approximately equal to that of the liner 2, an

aluminum'alloy being preferably employed.

The piston is grooved to receive packing rings 11, preferably of iron or steel. In other respects the piston may be of any suitable form and construction.

Inasmuch as the materials of the piston and of the cylinder wall have substantially or nearly the same coefficient of thermal expansion, a minimum working clearance may be provided for the piston and the objectionable slap and escape of lubricating oil into the combustion chamber which have characterized prior constructions are obviated.

The operation of my improved engine will be understood without further description as it is the same, with exception of thematters already noted, as that of the prior forms of construction. As has been stated, the piston at all times, while the engine is starting as well as after it has warmed up, has a minimum clearance. Furthermore, inasmuch as the lining sleeve "of bronze, or other suitable material, has a high thermal conductivity comparable to that of the piston and of the cylinder casting, the heat of combustion absorbed by the sleeve is rapidly conducted from its upper to its lower parts and is more uniformly distributed than is the case with lining sleeves of iron or steel. This .uniform distribution of the heat, as has been pointed out, minimizes the distortion of the cylinder wall and piston friction resulting from such distortion.

As has been indicated, the alloy materials used in the lining sleeves are more readil machined than is either iron or steel an especially in the case of bronze, the sleeve is not subject to corrosion and to change of properties resulting from the absorption of carbon, such as characterizes iron and steel liners.

It is to be understood that in referring herein to the metals forming the cylinder sleeves or liners as having co-eificients of expansion approximating those of the, piston and the cylinder casting, I intend by the use of the term approximate to cover any suitable metal whose co-eflicient of expansiori approaches those of the piston andthe cylinder casting relatively closely in comparison with the co-eflicient of expansion of iron.

.It will, of course, be understood with respect to the valvemechanism and other parts of the engine which are not shown in detail,

or not at all, that any of the suitable known intended to indicate the scope of applicants invention.

. What I claim is:

1. In an internal combustion motor, the combination with a composite cylinder comprising a casting of light weight metallic alloy with a high coefficient of thermal expansion and formed with a cylindrical wall liner being made of wear-resisting metallicalloy having a coeflicient of thermal expansion approximating that of :the cylinder casting alloy, of a piston operatively arranged in the liner and formed of light weight metallic alloy having a coefficient of thermal expansion approximating those of the cylinder casting and liner alloys.

2. In an internal combustion motor, the combination with a composite cylinder comprising a casting ofrlight weight metallic alloy with a high coeflicient of thermal expansion and formed with a cylindrical Wall having a cooling means on its exterior surface, and a tubular liner having its outside surface in close contact with the inner surface of the said cylindrical wall, the said liner being made of wear-resisting metallic alloy having a high coeificient of thermalconductivity and'a coefficient of thermal expansion approximating that of the cylinder casting alloy, of a piston operatively arranged in the liner and formed of light weight metallic alloy having a coefficient of. thermal expansion approximating those of the cylinder casting and liner alloys;

3. In an internal combustion motor, the combination With a composite cylinder comprising a casting of light weight metallic alloy with a high coeflicient of thermal expansion and formed With a cylindrical Wall having a cooling means on its exterior surface, and a tubular liner secured in the said cylindrical Wall by pouring the molten metal of one part against the solid metal of the other part, the said liner being made of Wear-resisting metallic alloy having a coeflicient of thermal expansion approximating that of the cylinder casting alloy, of a piston operatively arranged in the liner and formed of lightweight metallic alloy having a coefficient of thermal expansion ap proximating those of the cylinder casting and liner alloys.

4. In an internal combustion motor, the combination with a piston made of light weight metallic alloy having a higher coefficient of thermal expansion than iron, of a composite cylinder having an outer casting and a cylinder sleeve therein in which the piston is operatively mounted, the said sleeve being made of metallic alloy having a coefficient of thermal expansion approximating that of the metallic alloy of the piston.

5; In an internal combustion motor, the

combination, with a piston made of light weight metallic alloy having a higher coeffi cient of thermal expansion than iron, of a composite cylinder having an outer casting and a cylinder sleeve therein in which the piston is operatively mounted, the said sleeve being made of metallic alloy having a high co-eflicient of thermal conductivity in comparison with iron and a co-efiicient of thermal expansion approximating that of the metallic alloy of the piston.

. 6. In an internal combustion motor, the combination with a piston made of light weight metallic alloy having a higher coefficient of thermal expansion than iron, of a Working cylinder in which the piston is operatively mounted, the said cylinder having its Wall Withwhich the piston slidably en gages made of metal having a co-efficient of thermal expansion approximating that of the metallic alloy of the piston.

In testimony whereof I hereunto aflix my signature.

ALLEN B. NORTON. 

